server/core/ConfigurationManagerServant.java

//---PACKAGE DECLARATION---
package uk.org.iscream.core;

//---IMPORTS---
import uk.org.iscream.util.*;
import uk.org.iscream.componentmanager.*;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.*;
import java.io.*;

/**
 * This class is essentially a Configuration factory.
 * This class implements the Configurator IDL and allows
 * other classes in the system ot obtain their Configuration
 *
 * On construction it requires a reference to the RootPOA
 * to allow it to create Configuration objects to be
 * returned.
 *
 * It also relies on the System.properties to set internal values.
 *
 * ###
 * A point to note is that this class does NOT yet manage
 * created configurations which may cause memory problems!
 * ###
 *
 * @author  $Author: ajm4 $
 * @version $Id: ConfigurationManagerServant.java,v 1.15 2001/03/03 14:52:56 ajm4 Exp $
 */
class ConfigurationManagerServant extends ConfigurationManagerPOA {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.15 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---

    /**
     * Creates a new ConfiguratorServant
     * This class uses the System.properties to set internal values
     */
    ConfigurationManagerServant() {
        // assign some local variables
        _configPath = System.getProperty("uk.org.iscream.ConfigurationLocation");
        _systemConfigFile = System.getProperty("uk.org.iscream.SystemConfigurationFile");

        // load the system config
        loadSystemConfig();

        // log our status
        _logger.write(toString(), Logger.SYSINIT, "started");
        _logger.write(toString(), Logger.SYSMSG, "configuration location - " + _configPath);
        _logger.write(toString(), Logger.SYSMSG, "system configuration file - " + _systemConfigFile);
    }

//---PUBLIC METHODS---
    
    /**
     * Returns a Configuration object which contains
     * the configuration data requested by the calling
     * object.
     *
     * This method will look in the systemConfig file
     * for an entry for this "source", if there is no
     * entry it returns a refernce to the system
     * config.  If there are any errors in reading the 
     * configuration, it returns null, the caller is 
     * expected to be able to handle this.
     *
     * This method also checks to see if the system.conf
     * file has been updated and reloads its reference if
     * needed.
     *
     * @param source the configuration required
     * @return the Configuration
     */
    public Configuration getConfiguration(String source) {
        _logger.write(toString(), Logger.SYSMSG, "got request for " + source);

        
        // check to see if we need to reload the system config
        // because it has changed
        if (isModified(_systemConfig.getFileList(), _systemConfig.getLastModified())) {
            _logger.write(toString(), Logger.SYSMSG, "system config changed");
            loadSystemConfig();
        }

        // search config for group membership
        LinkedList groups = getGroupMembership(source);
        
        // if we are dealing with a Host.<hostname> request, then we also
        // want to look for ip address details, as configuration entries may relate to it
        // if we can't resolve it, we don't look.
        if (source.startsWith("Host.")) {
            // hostname is after Host.
            String hostname = source.substring(5);
            try {
                String ip = "Host." + InetAddress.getByName(hostname).getHostAddress();
                LinkedList ipGroups = getGroupMembership(ip);
                groups.addFirst(ip);
                groups.addAll(ipGroups);
            } catch (UnknownHostException e) {
                _logger.write(toString(), Logger.ERROR, "could not resolve hostname - " + hostname);
            }
        }

        // add the hosts individual config to the start of the list
        groups.addFirst(source);

        Iterator i = groups.iterator();
        String fileList = "";
        while (i.hasNext()) {
            String groupName = (String) i.next();
            _logger.write(toString(), Logger.DEBUG, "looking for config entry for - " + groupName);
            // we look for this entry in the systemConfig
            String configFile = _systemConfig.getProperty("config." + groupName);
            // if there is a config entry then
            if (configFile != null) {
                _logger.write(toString(), Logger.DEBUG, "looking for config tree in - " + configFile);
    
                // get the file list of includes etc + the system config
                String groupFileList = null;
                try {
                    groupFileList = getIncludedFiles(configFile, "") + ";";
                } catch (Exception e) {
                    // not sure what to do here
                    // so we just log the error
                    _logger.write(toString(), Logger.ERROR, "ERROR - " + e);
                }
                if (groupFileList != null) {
                    fileList += groupFileList;
                }
            } else {
                _logger.write(toString(), Logger.DEBUG, "no config entry for - " + groupName);
            }
        }
        // add the system config as the final check
        fileList = _systemConfigFile + ";" + fileList;
        _logger.write(toString(), Logger.DEBUG, "config tree - " + fileList);
        
        // build the configuration
        Configuration config = buildConfiguration(fileList);
        
        // if this is null at this point, then there will have been an error
        return config;
    }
    
    
    /**
     * When passed a file list and a current value for the lastModified
     * of the current configuration, this method compares the value
     * to the actual value of the configuration files to determine 
     * whether or not the configuration has been modified.
     *
     * @param fileList a list of files that the caller uses for configuration
     * @param lastModified the last modified date of the callers configuration
     *
     * @return whether or not the configuration has been modified
     */
    public boolean isModified(String fileList, long lastModified) {
        StringTokenizer st = new StringTokenizer(fileList, ";");
        long newLastModified;
        File currentFile;
        while (st.hasMoreTokens()) {
            currentFile = new File(_configPath, st.nextToken());
            newLastModified = currentFile.lastModified();
            if (newLastModified > lastModified) {
                return true;
            }
        }
        return false;
    }

    /**
     * Overrides the {@link java.lang.Object#toString() Object.toString()}
     * method to provide clean logging (every class should have this).
     *
     * This uses the uk.org.iscream.util.FormatName class
     * to format the toString()
     *
     * @return the name of this class and its CVS revision
     */
    public String toString() {
        return FormatName.getName(
            _name,
            getClass().getName(),
            REVISION);
    }

//---PRIVATE METHODS---

    /**
     * This is a recursive function private to this class.
     * It constructs a hierarchy of files as a ";" serperated
     * string which can be used to read in the configuration.
     * This function calls itself.
     * 
     * @param currentFile the current file to be processed
     * @param readFiles used for recursion purposes only, these are the files it has read so far 
     *
     * @return the current list that has been constructed
     *
     * @throws IOException if there is trouble reading the file
     * @throws FileNotFoundException is there is trouble finding the file
     * @throws CircularIncludeException this is if a circular include is detected
     */
    private String getIncludedFiles(String currentFile, String readFiles) throws IOException, FileNotFoundException, Exception {
        
        // check for circular include here
        if (hasDuplicate(currentFile, readFiles) || currentFile.equals(_systemConfigFile)) {
            throw new CircularIncludeException(currentFile + " is included more than once");
        }
        
        // if there wasn't, we're gonna use this file, so make a note of it as read
        // (note the use of the ";", this is for the hasDuplicate, function)
        readFiles = readFiles + currentFile + ";";

        Properties properties = new Properties();
        properties.load(new FileInputStream(new File(_configPath, currentFile)));
        
        // get the include property
        String includes = properties.getProperty("include");

        // if we're the last file with no includes, return our name
        if (includes == null) {
            return currentFile;
        
        // otherwise, recurse over our includes
        } else {
            StringTokenizer st = new StringTokenizer(includes, ";");
            String returnList= "";
            while (st.hasMoreTokens()) {
                returnList = getIncludedFiles(st.nextToken(), readFiles) + ";" + returnList;
            }
            
            return returnList + currentFile;
        }
    }

    /**
     * This simple method checks to see if a given 
     * file exists in the given list.
     *
     * @param file the file to check the list for
     * @param fileList the list to check
     *
     * @return if the given file appeard in the list
     */
    private boolean hasDuplicate(String file, String fileList) {
        StringTokenizer st = new StringTokenizer(fileList, ";");
        while (st.hasMoreTokens()) {
            if (file.equals(st.nextToken())) {
                return true;
            }
        }
        return false;
    }

    /**
     * Opens and loads the system configuration into the 
     * local reference _systemConfig
     */
    private void loadSystemConfig() {
        _logger.write(this.toString(), Logger.SYSMSG, "reloading " + _systemConfigFile);
        // get a reference to the system config and store it
        try {
            // create the properties for the configuration
            File systemConfigFile = new File(_configPath, _systemConfigFile);
            _systemConfigHolder = new Properties();
            _systemConfigHolder.load(new FileInputStream(systemConfigFile));
            
            // create the servant
            ConfigurationServant ref = new ConfigurationServant(_systemConfigHolder, _systemConfigFile, systemConfigFile.lastModified());
            org.omg.CORBA.Object objRef = _refman.getRootPOA().servant_to_reference(ref);
            
            // narrow it to a Configuration
            _systemConfig = ConfigurationHelper.narrow(objRef);
            
        } catch (Exception e) {
            _logger.write(toString(), Logger.FATAL, "ERROR: " + e.getMessage());
        }
    }

    /**
     * Parses the system configuration file
     * for group membership entries.
     *
     * It looks for all entries of group.<name>
     * which contain the given source name
     *
     * @param source the source to find membership for
     *
     * @return the list of groups that this source is a member of
     */
    private LinkedList getGroupMembership(String source) {
        _logger.write(toString(), Logger.DEBUG, "searching group members for - " + source);
        LinkedList groupMembership = new LinkedList();        
        Iterator i = new TreeSet(_systemConfigHolder.keySet()).iterator();
        while(i.hasNext()) {
            String key = (String) i.next();
            if (key.startsWith("group.")) {
                String group = _systemConfig.getProperty(key);
                // if it is in the group
                if (group.indexOf(source) != -1) {
                    groupMembership.add(key.substring(6));
                
                // if there are wildcards in the group
                } else if (group.indexOf("*") != -1) {
                    // check the wildcards apply to this srce
                    if( wildcardCheck(source, group)) {
                        groupMembership.add(key.substring(6));
                    }
                }
                
            }   
        }
        return groupMembership;
    }    

    /**
     * Checks that a given string is not matched within the
     * given list of strings. eg:<br>
     * <br>
     * Given "stue5de.ukc.ac.uk"<br>
     * And   "raptor.ukc.ac.uk;stue*.ukc.ac.uk<br>
     * <br>
     * This method would return true as there is a match
     * 
     * @param source the string to look for
     * @param group the group to search for a wilcard entry
     *
     * @return if there is a match
     */
    private boolean wildcardCheck(String source, String group) {
        boolean foundMatch = false;
        StringTokenizer st = new StringTokenizer(group, ";");
        // go through all the hosts in the group
        while (st.hasMoreTokens()) {
            String host = st.nextToken();
            // this host has wildcards
            if(host.indexOf("*") != -1) {
                StringTokenizer hostst = new StringTokenizer(host, "*");
                String part = "";
                int index = 0;
                // the first token will be everything at the start
                // unless it starts with a wildcard
                if(!host.startsWith("*")) {
                    part = hostst.nextToken();
                    if (source.startsWith(part)) {
                        foundMatch = true;
                        index = part.length();
                    }
                // all of the start of the string is matched
                } else {
                    foundMatch = true;
                }
                // if the start matched, we want to check the rest...
                if (foundMatch) {
                    while (hostst.hasMoreTokens()) {
                        part = hostst.nextToken();
                        // if the next section can't be matched
                        // then this isn't in the source
                        if(source.substring(index).indexOf(part) == -1) {
                            foundMatch = false;
                            // we don't want to look through any more of it
                            break;
                        } else {
                            foundMatch = true;
                            index += source.substring(index).indexOf(part) + part.length();
                        }
                    }
                    // if we reach here and we've found a match
                    // we want to check that the last part
                    // of the wildcard string is the last part
                    // of the source, if it is, we break out
                    // and finish as we've found a match.
                    // if the end of the wildcard is a *, then
                    // we don't care
                    if (!host.endsWith("*") && foundMatch) {
                        if ((source.endsWith(part))) {
                            _logger.write(toString(), Logger.DEBUG, "wildcard match found for - " + source + " in - " + host);
                            break;
                        // if there is no match, say so so we go round again
                        } else {
                            foundMatch = false;
                        }
                    } else if (foundMatch) {
                        _logger.write(toString(), Logger.DEBUG, "wildcard match found for - " + source + " in - " + host);
                        break;
                    }
                }
            }
        }
        return foundMatch;
    }


    /**
     * Build the properties as a Configuration to be 
     * returned to the caller
     *
     * @param fileList the list of files to build the configuration from
     *
     * @return the built Configuration
     */
    private Configuration buildConfiguration(String fileList) {
        Configuration config = null;

        // if there is an entry
        if (!fileList.equals("")) {
            try {
                
                // build the properites here from the filelist.... 
                StringTokenizer st = new StringTokenizer(fileList, ";");
                
                // some holders for variables
                File currentFile;
                long lastModified = 0, newLastModified = 0;
                Properties properties = null, prevProperties = null;
                
                // the root of all configurations will be the system config
                // so we need to open the properties of that
                Properties defaultProperties = new Properties();
                
                // This loop then iterates over the file list
                // creates the properties to be passed to the
                // Configuration constructor
                while (st.hasMoreTokens()) {
                    properties = new Properties(defaultProperties);
                    currentFile = new File(_configPath, st.nextToken());
                    newLastModified = currentFile.lastModified();
                    if (newLastModified > lastModified) {
                        lastModified = newLastModified;
                    }
                    properties.load(new FileInputStream(currentFile));
                    defaultProperties = properties;
                }

                // this creates the configuration, all nice, ready to be returned
                ConfigurationServant ref = new ConfigurationServant(properties, fileList, lastModified);
                org.omg.CORBA.Object objRef = _refman.getRootPOA().servant_to_reference(ref);
                config = ConfigurationHelper.narrow(objRef);
                _logger.write(toString(), Logger.DEBUG, "returning built configuration");
            } catch (Exception e) {
                // not sure what to do here
                // so we just log the error
                _logger.write(toString(), Logger.ERROR, "ERROR - " + e);
            }
            
        // if there isn't an entry for the requested config
        } else {
            _logger.write(toString(), Logger.DEBUG, "no configured config, returning " + _systemConfigFile);
            config = _systemConfig;
        }
        return config;
    }

//---ACCESSOR/MUTATOR METHODS---

//---ATTRIBUTES---

    /**
     * This is the friendly identifier of the
     * component this class is running in.
     * eg, a Filter may be called "filter1",
     * If this class does not have an owning
     * component,  a name from the configuration
     * can be placed here.  This name could also
     * be changed to null for utility classes.
     */
    private String _name = Core.NAME;

    /**
     * This holds a reference to the
     * system logger that is being used.
     */
    private Logger _logger = ReferenceManager.getInstance().getLogger();
    
    /**
     * A reference to the reference manager in use
     */
    private ReferenceManager _refman = ReferenceManager.getInstance();
    
    /**
     * The root path to all configurations
     */
    private String _configPath;
    
    /**
     * The name of the file that contains the system configuration
     */
    private String _systemConfigFile;
    
    /**
     * An instance of the system config
     */
    private Configuration _systemConfig;
    
    /**
     * The system config file represented by a
     * properties object.
     */
    private Properties _systemConfigHolder;
    
//---STATIC ATTRIBUTES---
    
}
Revision:	1.16
Committed:	Wed Mar 14 23:25:29 2001 UTC (23 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.15:	+9 -9 lines
Log Message:	The whole server package structure has been changed. Old Package: uk.ac.ukc.iscream.* New Package: uk.org.iscream.*
#	User	Rev	Content
1	ajm	1.3	//---PACKAGE DECLARATION---
2	tdb	1.16	package uk.org.iscream.core;
3	ajm	1.3
4			//---IMPORTS---
5	tdb	1.16	import uk.org.iscream.util.*;
6			import uk.org.iscream.componentmanager.*;
7	ajm	1.15	import java.net.InetAddress;
8			import java.net.UnknownHostException;
9	ajm	1.3	import java.util.*;
10			import java.io.*;
11
12			/**
13			* This class is essentially a Configuration factory.
14			* This class implements the Configurator IDL and allows
15			* other classes in the system ot obtain their Configuration
16			*
17			* On construction it requires a reference to the RootPOA
18			* to allow it to create Configuration objects to be
19			* returned.
20			*
21			* It also relies on the System.properties to set internal values.
22			*
23	ajm	1.6	* ###
24			* A point to note is that this class does NOT yet manage
25			* created configurations which may cause memory problems!
26			* ###
27			*
28	tdb	1.16	* @author $Author: ajm4 $
29			* @version $Id: ConfigurationManagerServant.java,v 1.15 2001/03/03 14:52:56 ajm4 Exp $
30	ajm	1.3	*/
31			class ConfigurationManagerServant extends ConfigurationManagerPOA {
32
33			//---FINAL ATTRIBUTES---
34
35			/**
36			* The current CVS revision of this class
37			*/
38	tdb	1.16	public final String REVISION = "$Revision: 1.15 $";
39	ajm	1.3
40			//---STATIC METHODS---
41
42			//---CONSTRUCTORS---
43
44			/**
45			* Creates a new ConfiguratorServant
46			* This class uses the System.properties to set internal values
47			*/
48	ajm	1.6	ConfigurationManagerServant() {
49	ajm	1.3	// assign some local variables
50	tdb	1.16	_configPath = System.getProperty("uk.org.iscream.ConfigurationLocation");
51			_systemConfigFile = System.getProperty("uk.org.iscream.SystemConfigurationFile");
52	ajm	1.3
53			// load the system config
54			loadSystemConfig();
55
56			// log our status
57	ajm	1.6	_logger.write(toString(), Logger.SYSINIT, "started");
58			_logger.write(toString(), Logger.SYSMSG, "configuration location - " + _configPath);
59			_logger.write(toString(), Logger.SYSMSG, "system configuration file - " + _systemConfigFile);
60	ajm	1.3	}
61
62			//---PUBLIC METHODS---
63
64			/**
65			* Returns a Configuration object which contains
66			* the configuration data requested by the calling
67			* object.
68			*
69			* This method will look in the systemConfig file
70			* for an entry for this "source", if there is no
71			* entry it returns a refernce to the system
72			* config. If there are any errors in reading the
73			* configuration, it returns null, the caller is
74			* expected to be able to handle this.
75			*
76			* This method also checks to see if the system.conf
77			* file has been updated and reloads its reference if
78			* needed.
79			*
80			* @param source the configuration required
81			* @return the Configuration
82			*/
83			public Configuration getConfiguration(String source) {
84	ajm	1.6	_logger.write(toString(), Logger.SYSMSG, "got request for " + source);
85	ajm	1.8
86	ajm	1.3
87			// check to see if we need to reload the system config
88			// because it has changed
89			if (isModified(_systemConfig.getFileList(), _systemConfig.getLastModified())) {
90	ajm	1.6	_logger.write(toString(), Logger.SYSMSG, "system config changed");
91	ajm	1.3	loadSystemConfig();
92			}
93
94	ajm	1.8	// search config for group membership
95			LinkedList groups = getGroupMembership(source);
96	ajm	1.15
97			// if we are dealing with a Host.<hostname> request, then we also
98			// want to look for ip address details, as configuration entries may relate to it
99			// if we can't resolve it, we don't look.
100			if (source.startsWith("Host.")) {
101			// hostname is after Host.
102			String hostname = source.substring(5);
103			try {
104			String ip = "Host." + InetAddress.getByName(hostname).getHostAddress();
105			LinkedList ipGroups = getGroupMembership(ip);
106			groups.addFirst(ip);
107			groups.addAll(ipGroups);
108			} catch (UnknownHostException e) {
109			_logger.write(toString(), Logger.ERROR, "could not resolve hostname - " + hostname);
110			}
111			}
112	ajm	1.3
113	ajm	1.8	// add the hosts individual config to the start of the list
114			groups.addFirst(source);
115	ajm	1.3
116	ajm	1.8	Iterator i = groups.iterator();
117			String fileList = "";
118			while (i.hasNext()) {
119			String groupName = (String) i.next();
120	ajm	1.11	_logger.write(toString(), Logger.DEBUG, "looking for config entry for - " + groupName);
121	ajm	1.8	// we look for this entry in the systemConfig
122			String configFile = _systemConfig.getProperty("config." + groupName);
123	ajm	1.11	// if there is a config entry then
124			if (configFile != null) {
125			_logger.write(toString(), Logger.DEBUG, "looking for config tree in - " + configFile);
126
127			// get the file list of includes etc + the system config
128			String groupFileList = null;
129			try {
130			groupFileList = getIncludedFiles(configFile, "") + ";";
131			} catch (Exception e) {
132			// not sure what to do here
133			// so we just log the error
134			_logger.write(toString(), Logger.ERROR, "ERROR - " + e);
135			}
136			if (groupFileList != null) {
137			fileList += groupFileList;
138			}
139			} else {
140			_logger.write(toString(), Logger.DEBUG, "no config entry for - " + groupName);
141	tdb	1.12	}
142	ajm	1.3	}
143	ajm	1.8	// add the system config as the final check
144	tdb	1.13	fileList = _systemConfigFile + ";" + fileList;
145	ajm	1.8	_logger.write(toString(), Logger.DEBUG, "config tree - " + fileList);
146
147			// build the configuration
148			Configuration config = buildConfiguration(fileList);
149	ajm	1.3
150			// if this is null at this point, then there will have been an error
151			return config;
152			}
153
154
155			/**
156			* When passed a file list and a current value for the lastModified
157			* of the current configuration, this method compares the value
158			* to the actual value of the configuration files to determine
159			* whether or not the configuration has been modified.
160			*
161			* @param fileList a list of files that the caller uses for configuration
162			* @param lastModified the last modified date of the callers configuration
163			*
164			* @return whether or not the configuration has been modified
165			*/
166			public boolean isModified(String fileList, long lastModified) {
167			StringTokenizer st = new StringTokenizer(fileList, ";");
168			long newLastModified;
169			File currentFile;
170			while (st.hasMoreTokens()) {
171			currentFile = new File(_configPath, st.nextToken());
172			newLastModified = currentFile.lastModified();
173			if (newLastModified > lastModified) {
174			return true;
175			}
176			}
177			return false;
178			}
179	ajm	1.6
180	ajm	1.3	/**
181			* Overrides the {@link java.lang.Object#toString() Object.toString()}
182			* method to provide clean logging (every class should have this).
183			*
184	tdb	1.16	* This uses the uk.org.iscream.util.FormatName class
185	ajm	1.6	* to format the toString()
186			*
187	ajm	1.3	* @return the name of this class and its CVS revision
188			*/
189			public String toString() {
190	ajm	1.6	return FormatName.getName(
191			_name,
192			getClass().getName(),
193			REVISION);
194	ajm	1.3	}
195
196			//---PRIVATE METHODS---
197
198			/**
199			* This is a recursive function private to this class.
200			* It constructs a hierarchy of files as a ";" serperated
201			* string which can be used to read in the configuration.
202			* This function calls itself.
203			*
204			* @param currentFile the current file to be processed
205	ajm	1.4	* @param readFiles used for recursion purposes only, these are the files it has read so far
206			*
207	ajm	1.3	* @return the current list that has been constructed
208			*
209			* @throws IOException if there is trouble reading the file
210			* @throws FileNotFoundException is there is trouble finding the file
211	ajm	1.4	* @throws CircularIncludeException this is if a circular include is detected
212	ajm	1.3	*/
213	ajm	1.4	private String getIncludedFiles(String currentFile, String readFiles) throws IOException, FileNotFoundException, Exception {
214
215			// check for circular include here
216			if (hasDuplicate(currentFile, readFiles) \|\| currentFile.equals(_systemConfigFile)) {
217			throw new CircularIncludeException(currentFile + " is included more than once");
218			}
219
220			// if there wasn't, we're gonna use this file, so make a note of it as read
221			// (note the use of the ";", this is for the hasDuplicate, function)
222			readFiles = readFiles + currentFile + ";";
223
224	ajm	1.3	Properties properties = new Properties();
225			properties.load(new FileInputStream(new File(_configPath, currentFile)));
226	ajm	1.4
227			// get the include property
228	ajm	1.3	String includes = properties.getProperty("include");
229	ajm	1.4
230			// if we're the last file with no includes, return our name
231	ajm	1.3	if (includes == null) {
232			return currentFile;
233	ajm	1.4
234			// otherwise, recurse over our includes
235	ajm	1.3	} else {
236			StringTokenizer st = new StringTokenizer(includes, ";");
237			String returnList= "";
238			while (st.hasMoreTokens()) {
239	ajm	1.4	returnList = getIncludedFiles(st.nextToken(), readFiles) + ";" + returnList;
240	ajm	1.3	}
241	ajm	1.4
242	ajm	1.3	return returnList + currentFile;
243			}
244			}
245
246			/**
247	ajm	1.4	* This simple method checks to see if a given
248			* file exists in the given list.
249			*
250			* @param file the file to check the list for
251			* @param fileList the list to check
252			*
253			* @return if the given file appeard in the list
254			*/
255			private boolean hasDuplicate(String file, String fileList) {
256			StringTokenizer st = new StringTokenizer(fileList, ";");
257			while (st.hasMoreTokens()) {
258			if (file.equals(st.nextToken())) {
259			return true;
260			}
261			}
262			return false;
263			}
264
265			/**
266	ajm	1.3	* Opens and loads the system configuration into the
267			* local reference _systemConfig
268			*/
269			private void loadSystemConfig() {
270	ajm	1.6	_logger.write(this.toString(), Logger.SYSMSG, "reloading " + _systemConfigFile);
271	ajm	1.3	// get a reference to the system config and store it
272			try {
273			// create the properties for the configuration
274			File systemConfigFile = new File(_configPath, _systemConfigFile);
275	ajm	1.8	_systemConfigHolder = new Properties();
276			_systemConfigHolder.load(new FileInputStream(systemConfigFile));
277
278	ajm	1.3	// create the servant
279	ajm	1.8	ConfigurationServant ref = new ConfigurationServant(_systemConfigHolder, _systemConfigFile, systemConfigFile.lastModified());
280	ajm	1.6	org.omg.CORBA.Object objRef = _refman.getRootPOA().servant_to_reference(ref);
281	ajm	1.3
282			// narrow it to a Configuration
283			_systemConfig = ConfigurationHelper.narrow(objRef);
284
285			} catch (Exception e) {
286	ajm	1.6	_logger.write(toString(), Logger.FATAL, "ERROR: " + e.getMessage());
287	ajm	1.3	}
288			}
289
290	ajm	1.8	/**
291			* Parses the system configuration file
292			* for group membership entries.
293			*
294			* It looks for all entries of group.<name>
295			* which contain the given source name
296			*
297			* @param source the source to find membership for
298			*
299			* @return the list of groups that this source is a member of
300			*/
301			private LinkedList getGroupMembership(String source) {
302	ajm	1.15	_logger.write(toString(), Logger.DEBUG, "searching group members for - " + source);
303	ajm	1.8	LinkedList groupMembership = new LinkedList();
304			Iterator i = new TreeSet(_systemConfigHolder.keySet()).iterator();
305			while(i.hasNext()) {
306			String key = (String) i.next();
307			if (key.startsWith("group.")) {
308			String group = _systemConfig.getProperty(key);
309	ajm	1.15	// if it is in the group
310	ajm	1.8	if (group.indexOf(source) != -1) {
311			groupMembership.add(key.substring(6));
312	ajm	1.15
313			// if there are wildcards in the group
314			} else if (group.indexOf("*") != -1) {
315			// check the wildcards apply to this srce
316			if( wildcardCheck(source, group)) {
317			groupMembership.add(key.substring(6));
318			}
319	ajm	1.8	}
320	ajm	1.15
321	ajm	1.8	}
322			}
323			return groupMembership;
324			}
325	ajm	1.15
326			/**
327			* Checks that a given string is not matched within the
328			* given list of strings. eg:<br>
329			* <br>
330			* Given "stue5de.ukc.ac.uk"<br>
331			* And "raptor.ukc.ac.uk;stue*.ukc.ac.uk<br>
332			* <br>
333			* This method would return true as there is a match
334			*
335			* @param source the string to look for
336			* @param group the group to search for a wilcard entry
337			*
338			* @return if there is a match
339			*/
340			private boolean wildcardCheck(String source, String group) {
341			boolean foundMatch = false;
342			StringTokenizer st = new StringTokenizer(group, ";");
343			// go through all the hosts in the group
344			while (st.hasMoreTokens()) {
345			String host = st.nextToken();
346			// this host has wildcards
347			if(host.indexOf("*") != -1) {
348			StringTokenizer hostst = new StringTokenizer(host, "*");
349			String part = "";
350			int index = 0;
351			// the first token will be everything at the start
352			// unless it starts with a wildcard
353			if(!host.startsWith("*")) {
354			part = hostst.nextToken();
355			if (source.startsWith(part)) {
356			foundMatch = true;
357			index = part.length();
358			}
359			// all of the start of the string is matched
360			} else {
361			foundMatch = true;
362			}
363			// if the start matched, we want to check the rest...
364			if (foundMatch) {
365			while (hostst.hasMoreTokens()) {
366			part = hostst.nextToken();
367			// if the next section can't be matched
368			// then this isn't in the source
369			if(source.substring(index).indexOf(part) == -1) {
370			foundMatch = false;
371			// we don't want to look through any more of it
372			break;
373			} else {
374			foundMatch = true;
375			index += source.substring(index).indexOf(part) + part.length();
376			}
377			}
378			// if we reach here and we've found a match
379			// we want to check that the last part
380			// of the wildcard string is the last part
381			// of the source, if it is, we break out
382			// and finish as we've found a match.
383			// if the end of the wildcard is a *, then
384			// we don't care
385			if (!host.endsWith("*") && foundMatch) {
386			if ((source.endsWith(part))) {
387			_logger.write(toString(), Logger.DEBUG, "wildcard match found for - " + source + " in - " + host);
388			break;
389			// if there is no match, say so so we go round again
390			} else {
391			foundMatch = false;
392			}
393			} else if (foundMatch) {
394			_logger.write(toString(), Logger.DEBUG, "wildcard match found for - " + source + " in - " + host);
395			break;
396			}
397			}
398			}
399			}
400			return foundMatch;
401			}
402
403	ajm	1.8
404			/**
405			* Build the properties as a Configuration to be
406			* returned to the caller
407			*
408			* @param fileList the list of files to build the configuration from
409			*
410			* @return the built Configuration
411			*/
412			private Configuration buildConfiguration(String fileList) {
413			Configuration config = null;
414
415			// if there is an entry
416	ajm	1.10	if (!fileList.equals("")) {
417	ajm	1.8	try {
418
419			// build the properites here from the filelist....
420			StringTokenizer st = new StringTokenizer(fileList, ";");
421
422			// some holders for variables
423			File currentFile;
424	tdb	1.14	long lastModified = 0, newLastModified = 0;
425			Properties properties = null, prevProperties = null;
426	ajm	1.8
427			// the root of all configurations will be the system config
428			// so we need to open the properties of that
429			Properties defaultProperties = new Properties();
430
431			// This loop then iterates over the file list
432			// creates the properties to be passed to the
433			// Configuration constructor
434	tdb	1.13	while (st.hasMoreTokens()) {
435	ajm	1.8	properties = new Properties(defaultProperties);
436			currentFile = new File(_configPath, st.nextToken());
437			newLastModified = currentFile.lastModified();
438			if (newLastModified > lastModified) {
439			lastModified = newLastModified;
440			}
441			properties.load(new FileInputStream(currentFile));
442			defaultProperties = properties;
443	tdb	1.13	}
444	ajm	1.8
445			// this creates the configuration, all nice, ready to be returned
446			ConfigurationServant ref = new ConfigurationServant(properties, fileList, lastModified);
447			org.omg.CORBA.Object objRef = _refman.getRootPOA().servant_to_reference(ref);
448			config = ConfigurationHelper.narrow(objRef);
449	tdb	1.13	_logger.write(toString(), Logger.DEBUG, "returning built configuration");
450	ajm	1.8	} catch (Exception e) {
451			// not sure what to do here
452			// so we just log the error
453	ajm	1.10	_logger.write(toString(), Logger.ERROR, "ERROR - " + e);
454	ajm	1.8	}
455
456			// if there isn't an entry for the requested config
457			} else {
458			_logger.write(toString(), Logger.DEBUG, "no configured config, returning " + _systemConfigFile);
459			config = _systemConfig;
460			}
461			return config;
462			}
463
464	ajm	1.3	//---ACCESSOR/MUTATOR METHODS---
465
466			//---ATTRIBUTES---
467
468			/**
469	ajm	1.6	* This is the friendly identifier of the
470			* component this class is running in.
471			* eg, a Filter may be called "filter1",
472			* If this class does not have an owning
473			* component, a name from the configuration
474			* can be placed here. This name could also
475			* be changed to null for utility classes.
476			*/
477			private String _name = Core.NAME;
478
479			/**
480			* This holds a reference to the
481			* system logger that is being used.
482	ajm	1.3	*/
483	ajm	1.6	private Logger _logger = ReferenceManager.getInstance().getLogger();
484	ajm	1.3
485			/**
486	ajm	1.6	* A reference to the reference manager in use
487	ajm	1.3	*/
488	ajm	1.6	private ReferenceManager _refman = ReferenceManager.getInstance();
489	ajm	1.3
490			/**
491			* The root path to all configurations
492			*/
493			private String _configPath;
494
495			/**
496			* The name of the file that contains the system configuration
497			*/
498			private String _systemConfigFile;
499
500			/**
501			* An instance of the system config
502			*/
503			private Configuration _systemConfig;
504	ajm	1.8
505			/**
506			* The system config file represented by a
507			* properties object.
508			*/
509			private Properties _systemConfigHolder;
510	ajm	1.3
511			//---STATIC ATTRIBUTES---
512
513			}